The chamber was pinned, because the rifle was deemed not safe to shoot anyway, if it was pinned by the military.
These were often used as 'Drill' weapons, for doing and practicing Parade Drill by Cadets mostly. The red and white stripe denotes it as a Drill Only gun.
The only way to make it a safe shooter, is to source a decent condition barrel, and have it installed by someone that knows what they are doing, and that has a suitable supply of spares to make sure that the correct length bolt, among other things, gets installed.
30-ish years ago, there were literally buckets of decent barrels available for ~$10 per, at gun shows. Nobody wanted them. Not so much these days.
If you buy one, use it for parts, or as the wall hanger it is.
If the one they are using as their poster child, is to go by, they are in pretty sorry condition too. Pass.